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Engine

Problems with the engine sensors: symptoms, cost and affected models

We have documented 29 faults with the engine sensors in 28 engines, affecting 177 models of car in our database. The most important by severity and frequency: VP44 injection pump and air mass meter failure (2.0 DTI and 2.2 DTI), clogged particulate filter or faulty pressure sensor (2.0 TDI) and crankshaft position sensor failure (TDC sensor) (1.4 and 1.6 8v). At an independent garage, the repair costs from €100 to €3,000 depending on the engine or car.[1][2][3][4]

Documented faults
29
2 of high or critical severity
Engines
28
with at least one fault on this part
Affected models
177
car generations in our database
Garage repair
€100–€3,000
Depending on engine and car, including VAT

4 sourcesHow we work

How it works and why it fails

Engine sensors

The control unit manages the engine using information from many sensors: crankshaft position, lambda sensors, air mass meter, pressure, temperature and so on. When one gives wrong readings, the engine can run badly, turn on the warning light or fail to start, even though the mechanics are fine.

What to do

An OBD reader shows the fault code and helps to locate the sensor. Before replacing it, check the connectors and wiring: many sensor faults are really a corroded connector or a chafed wire. A crankshaft sensor failure can stop the engine while driving.

General explanation by MotorFiable. The specific faults of each engine and car, with their sources, are on the linked pages.

Common symptoms

The symptoms that come up most often in the documented faults with the engine sensors. Open each one to see what other faults cause it.

Problems with the engine sensors by engine

From most to least important (severity × frequency). Each page details the affected versions and years, symptoms, cost and how to check for it.

  1. 1High severityFrequency: Occasional2.0 DTI and 2.2 DTIVP44 injection pump and air mass meter failureGerman Wikipedia documents recurring failures of the Bosch VP44 injection pump and the air mass meter in the early years of this engine. An owner testimony for this engine describes the pump being replaced at 192,500 km, at a cost the owner calls «prohibitive».
  2. 2Medium severityFrequency: Common2.0 TDIClogged particulate filter or faulty pressure sensorThe 2.0 TDI's particulate filter clogs if the car mostly makes short journeys, because it never gets to regenerate; sometimes the fault is just the differential pressure sensor. Cleaning it costs around €200 and replacing it, €800 to €3,000.Repair (garage): €800–€3,000
  3. 3Medium severityFrequency: Common1.4 and 1.6 8vCrankshaft position sensor failure (TDC sensor)The crankshaft position sensor (capteur PMH, or TDC sensor) appears repeatedly in the reliability sources for the Clio II, the Kangoo I and the Dacia Logan I with this engine, with hard cold starting or stalling as the main symptoms. It is a cheap part, but the failure can leave you stranded.
  4. 4Medium severityFrequency: Common1.4 and 1.6 16vCrankshaft position sensor failureThe crankshaft position sensor (capteur PMH) appears repeatedly in the reliability sources for almost every generation with this engine, with hard cold starting, stalling or the car cutting out unexpectedly. It is a cheap part, but the failure can leave you stranded.
  5. 5Medium severityFrequency: OccasionalBMW B57AdBlue/SCR system fault (NOx sensors, heater and pump)A specialist garage considers the B57's AdBlue/SCR system the fault that most often leaves cars immobilised: a NOx sensor, the quality sensor, the heater or the pump usually fails, and topping up the tank rarely stops the countdown of remaining starts.
  6. 6Medium severityFrequency: Occasional1.2 8v FireSensor failures: lambda sensor and crankshaft position sensor (TDC)The 1.2 8v Fire can suffer sensor faults: the lambda sensor (warning light, rough running) and, in the Fiat Punto, the crankshaft position sensor (TDC sensor), linked to misfires. These are minority issues, but they recur across several models with this engine.
  7. 7Medium severityFrequency: Occasional1.6 and 2.0 MultiJet IIInjector faults and DPF particulate sensor failureIn some batches, a fault in the injection system or in the DPF particulate sensor turns on the engine fault warning light. In the Fiat Doblò, worn injectors or injectors with poor atomisation are also cited as a cause of power loss, higher consumption and black smoke when accelerating.
  8. 8Medium severityFrequency: OccasionalM112 / M113Crankshaft position sensor failureYes: according to a German guide, a faulty crankshaft sensor is the only thing that causes any grief from time to time on the M113 V8, and there are reports on the M112 V6 too. It can make the engine lose power, stall or fail to start.
  9. 9Medium severityFrequency: Occasional1.0 SCe (B4D)Jerking, rough idle or warning light from sensors and ignition coilsThe 1.0 SCe can jerk, run unevenly or light up the engine fault warning light because of sensor faults (lambda sensor), ignition coils or injection management. It is a recurring but minority issue in the sources consulted, unrelated to a mechanical problem with the engine block.
  10. 10Medium severityFrequency: Occasional1.2 16vProbe and sensor faults (crankshaft position, throttle body)The 1.2 16V can fail because of specific probes or sensors, above all the crankshaft position sensor (TDC sensor) and the throttle body, with the engine warning light on or difficulty starting. Documented on the Clio II, Clio III and Kangoo I.
  11. 11Medium severityFrequency: OccasionalVolvo 5 cilindros gasolinaFaulty electronic throttle body with unstable idleOn the 2000 to 2002 petrol Volvo V70 II, Gebrauchtwagenberater says the electronic throttle body wears out early and causes an uneven idle and stalling. We have found no data for other years or other cars with this engine.
  12. 12High severityFrequency: RareMitsubishi PHEVCorroded air flow sensor: the petrol engine does not start to charge the batteryOn 2014 Outlander PHEVs, sulphur from the intake hose can corrode the resistor in the air flow sensor. The petrol engine then does not start to charge the traction battery and the car may suddenly stop. Safety Gate records it (A12/1947/19); the DVSA counts only 12 cars.
  13. 13Low severityFrequency: CommonM111Mass air flow sensor failureYes: the M111 mass air flow sensor can fail with use and cause jerking or rough running. English-language Wikipedia documents it on the W210 E-Class, and a French owner survey of the SLK R170 names it as the most-cited fault on that model.
  14. 14Low severityFrequency: Common1.4 and 1.6 TU3/TU5Sensors that fail: lambda sensor and temperature sensorThe lambda sensor and the coolant temperature sensor are, along with the coils, the components most cited as faulty: they cause an unstable idle, the engine warning light coming on or a cooling fan that does not behave normally.Appears at around 25,000 km
  15. 15Low severityFrequency: Common1.8 T 20vAir mass meter (MAF sensor) failureThe air mass meter (MAF sensor) fails fairly often on the 1.8T: on the 150 hp Audi A3 it appears in 3 of the 11 reports collected, and it is also documented on the 180 and 225 hp Audi TT. It causes hesitation and loss of power; it is fixed by replacing the sensor.
  16. 16Low severityFrequency: Common1.9 TDIDirty or faulty air flow meter on the 1.9 TDI (loss of power)The air flow meter is a known weak point of the 1.9 TDI: it gets dirty or gives wrong readings, and the control unit limits the engine, causing a sudden loss of power. It is cheap to fix and does not damage the engine.Repair (garage): €100–€300
  17. 17Medium severityFrequency: Rare2.0 MR20DE / 2.5 QR25DEFaulty throttle body on the X-Trail T31 2.5 (QR25DE)Hella documents an X-Trail T31 2.5 (QR25DE, 2007-2014) with loss of power and irregular engine running caused by a throttle body defect, with intermittent voltage codes from the throttle position sensor.
  18. 18Low severityFrequency: OccasionalBMW M47Faulty air flow meter on the BMW M47 (loss of power)On the 2.0 M47 diesel the air flow meter appears among parts that can fail with age and cause loss of power or judder. It is fixed by replacing the sensor; other causes must be ruled out first.Repair (garage): €100–€300
  19. 19Low severityFrequency: OccasionalBMW M57Faulty air flow meter on the BMW M57 (loss of power)The air flow meter is a known fault on six-cylinder M57 diesels: over time it loses accuracy and the car pulls less. It is a cheap repair compared with the turbo or injection.Repair (garage): €100–€300
  20. 20Low severityFrequency: Occasional1.9 JTD/Multijet and 2.4 JTDFaulty air flow meter on the 1.9 JTD / Multijet (loss of power)On the 1.9 JTD and 1.9 CDTI the air flow meter repeatedly appears among ancillary faults: loss of power. It is fixed by replacing the sensor after ruling out air leaks and the EGR.Repair (garage): €100–€300
  21. 21Low severityFrequency: Occasional2.2 CDI (OM646)Particulate filter (DPF) sensor failureThe OM646 introduced an additive-free particulate filter from mid-2003, but its sensor fails relatively often according to a specialist German source. Also, not all units of the period were fitted with it at the factory, so you should check whether the specific car has one before assuming a fault.
  22. 22Low severityFrequency: OccasionalMIVEC gasolinaFaulty throttle body on the Colt 1.1, 1.3 and 1.5The petrol Colts (1.1, 1.3 and 1.5) have a reputation for toughness, but Gebrauchtwagenberater and Autoplenum cite occasional throttle body defects, on 2005 to 2008 cars according to the latter; no source details symptoms or cost.
  23. 23Low severityFrequency: Occasional1.6 DIG-TLambda sensor and other engine sensor failuresAn engine warning light caused by a lambda sensor or other sensor failure is one of the most repeated issues in the owner reviews consulted for this engine, although it is almost always fixed by replacing the sensor, with no damage to the engine.
  24. 24Low severityFrequency: Occasional1.0 VVT-iFaulty lambda sensor (P0420 code) on the 1.0 VVT-iOn the 1.0 VVT-i (1KR-FE) in the Aygo, C1 and 107/108, the lambda sensor, especially the one upstream of the catalytic converter, is documented as failing at high mileage and leaving code P0420 and the engine warning light. It is a cheap repair and does not damage the engine.
  25. 25Low severityFrequency: Occasional1.4, 1.6 and 1.8 VVT-iAir mass meter and lambda sensor failuresOn a minority of Corolla, Avensis and Corolla Verso cars with this engine, the air mass meter (MAF sensor) or the lambda sensor gives wrong readings and lights up the engine warning light; it is a relatively simple repair and does not compromise the engine.
  26. 26Low severityFrequency: Occasional1.4 16v and 1.6 MPI/FSIFaulty lambda sensors on the 1.6 FSIThe 1.6 FSI direct-injection engine (Golf V, Touran) has documented lambda sensor faults that trigger the engine warning light and cause a rough idle. It is a low-severity fault, but it should be fixed to avoid overloading the catalytic converter.
  27. 27Low severityFrequency: Rare2.2 CDI (OM646)Faulty air flow meter on the 220 CDI (OM 611 and OM 646)On the 220 CDI the air flow meter fails in a minority of units: 14 of the 503 opinions collected by fiches-auto. It alters the air/fuel mixture and is cheap to repair.Repair (garage): €100–€300
  28. 28Low severityFrequency: Rare2.2/2.5 dCiDirty or misreading mass airflow sensorThe 2.2 dCi's mass airflow sensor can get dirty and give incorrect readings; the Almera reliability report points to it as a known problem of the engine, although with few recorded cases.
  29. 29Low severityFrequency: Rare1.0 MPIOccasional sensor or throttle body faults (isolated cases)The Škoda Fabia III with the 1.0 MPI records an isolated case of throttle body failure (at 80,000 km) or lambda sensor failure. These are one-off cases, with no pattern, within a sample the sources describe as mechanically stable.

Engines with faults with the engine sensors

Problems with the engine sensors by make

Problems with the engine sensors in your car

36 cars have several documented faults with the engine sensors. Choose yours to see only the ones that affect them, by engine and by year.

Audi 2
BMW 3
Dacia 4
Fiat 2
Mercedes-Benz 9
Nissan 1
Opel 3
Renault 4
Seat 2
Škoda 3
Volkswagen 3

How much it costs to repair a fault with the engine sensors

Sorted from the most expensive repair to the cheapest. Prices in Spain including VAT (parts and labour); what each figure includes is on its page.

How we calculate costs · The most expensive repairs across all engines

OBD fault codes with the engine sensors

The codes the ECU usually stores when this part fails: what they mean, causes and what to check.

Frequently asked questions

Which engines have the most faults with the engine sensors?

By severity and frequency, the 2.0 DTI and 2.2 DTI (VP44 injection pump and air mass meter failure, high severity), the 2.0 TDI (clogged particulate filter or faulty pressure sensor, medium severity), the 1.4 and 1.6 8v (crankshaft position sensor failure (TDC sensor), medium severity), the 1.4 and 1.6 16v (crankshaft position sensor failure, medium severity), the BMW B57 (AdBlue/SCR system fault (NOx sensors, heater and pump), medium severity) and the 1.2 8v Fire (sensor failures: lambda sensor and crankshaft position sensor (TDC), medium severity). In total we have documented 28 engines with faults with the engine sensors.

How much does it cost to repair a fault with the engine sensors?

It depends a lot on the engine or car. At an independent garage, from €100 to €3,000, including VAT, based on the 6 faults with a documented cost. The most expensive is clogged particulate filter or faulty pressure sensor (2.0 TDI).

What symptoms does a fault with the engine sensors cause?

The most frequently cited in the documented faults: engine fault warning light (check engine), gradual loss of power, hard starting or engine will not start, engine stalls or cuts out while driving, increase in fuel consumption and jerking or juddering when accelerating.

Sources

Every fact on this page links to its source. If you find an error, let us know.

  1. Caudalímetro o sensor MAF: qué es, cómo funciona y cuáles son las averías más frecuentesDiariomotor · Motoring press · consulted 30 October 2026 · in Spanish
  2. Filtro de partículas: ¿mejor limpiar o sustituir?Autofácil · Motoring press · published 7 April 2022 · consulted 26 September 2026 · in Spanish
  3. Cuánto cuesta sustituir el filtro de partículas de un coche diéselDiariomotor · Motoring press · published 17 January 2020 · consulted 26 September 2026 · in Spanish
  4. Maxi-fiche fiabilité - Audi A4 (2007-2015) : belle, mais capricieuseCaradisiac · Motoring press · published 1 April 2023 · consulted 26 September 2026 · in French